Mrs Curtis-Thomas said: "The overwhelming majority of medical studies have shown that passive smoking is severely detrimental to health.

"Smoking causes 43,000 cancer deaths a year, more than 1,000 of them in Liverpool, and a ban would encourage smokers to kick the habit."

But equally, only one of the region's MPs, West Derby's Bob Wareing, has signed a rival motion rejecting a smoking ban in pubs.

Mr Wareing said: "A ban would be illiberal and would remove the right of millions of law-abiding people to enjoy a relaxing drink and a smoke in their local pubs."

He said that it should be left to the pub landlord "to decide what kind of establishment he wishes to run, having due regard to customers and staff".

Meanwhile the Department of Health has launched a major consultation exercise on smoking in public places which will form part of a government white paper to be published towards the end of the year.

A Liverpool city council spokesman said today: "We knew the bill is not going to be easy to pass, but we're confident of receiving crossparty support from MPs and peers.

"Ideally, we would prefer national legislation to impose a smoking ban throughout the country, but in the meantime we're prepared to pursue this to protect and improve the health of people in Liverpool."

The move follows changes to a directive secured by Merseyside MEP Chris Davies. All EU governments will now have the option of making them compulsory.

The pictures, pioneered in Canada, show diseased lungs, gangrenous legs and other shocking illustrations of the health risks associated with smoking.

Other designs link smoking to male impotency.

Forty-two photos have been issued, three to accompany each of the 14 written warnings which currently appear on cigarette packs in the UK.

Evidence from Canada shows that 44% of smokers say the illustrations have increased their motivation to try and give up smoking.

Mr Davies, leader of the Liberal Democrats in Europe, said the aim was to curb peer pressure which leads to young people taking their first smoke, often before they are 16.

He said: "We have to break the impression among teenagers that smoking is cool and sexy.

"I can think of few things more likely to be effective than illustrating the proven risk that tobacco use leads to reduced sexual potency."

He added: "Adults should be free to smoke in private, but government health policy should aim to make sure that people are well informed about possible dangers from all drugs, and tobacco is the biggest killer of all."

He urged Health Secretary John Reid to introduce the pictures on all packs as soon as possible.